Humans are more related to fish than once thought

Many if not all of the biological research paradigms on the fact that because of evolution the basic genetic constitution is largely conserved across species. Understanding of various molecular, cellular or genetic mechanisms through experiments, therefore, is first conducted on primary organisms (like microbes) and then moving up the ladder of relatedness from fishes to mammals and primates.

Occasionally there are studies which reiterate this fact with greater certainty. Like this one for example by Duke University which titles ‘Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells’ [1].

The research team led by Dr. John Rawl generated genome-wide mRNA and chromatin (DNA + histone) data from adult intestinal epithelial cells (IECs) in four distinct species. These were zebrafish, stickleback, mouse, and humans separated from a common ancestor about 420 million years ago. The aim of this study was to determine the conserved IEC functions through the common transcriptional regulation of genes.

The broader premise was based on the fact that the intestinal epithelium shares similar physiological functions across the species, however, the underlying transcriptional regulatory mechanisms behind this is not known in the course of evolution.

The results showed high common regulation and conservation of gene expression and sequence conservation from fish to mammals and in fact, the most highly conserved expression was seen in Zebrafish. Many of these shared genes have been exploited by the scientists in the study of diabetes, inflammatory bowel diseases and obesity. In some ways, it’s like saying that in the hierarchy of evolution the genetics of digestion remain remarkably similar from fish up to in human.

As per an article published in The Herald Sun, Rawls said: “These results indicate that the intestines of humans and fishes share more in common than once presumed, making it possible to look into the guts of fish and other related animals to learn about the origins of human intestinal conditions” [2].

Reference:
1] Colin R. Lickwar, J. Gray Camp, Matthew Weiser, Jordan L. Cocchiaro, David M. Kingsley, Terrence S. Furey, Shehzad Z. Sheikh, John F. Rawls Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells PLoS Biology 29 August 2017
2] www.heraldsun.com/news/local/article170272467.html